The German language is different from the English language. Each language has its own words, sentences and grammar. However, I discovered from a website that the German and English languages share 60% of their vocabulary? I would like to know to what extent is it true?
It seems to be true in terms of lexical similarity
In linguistics, lexical similarity is a measure of the degree to which the word sets of two given languages are similar. A lexical similarity of 1 (or 100%) would mean a total overlap between vocabularies, whereas 0 means there are no common words.
There are different ways to define the lexical similarity and the results vary accordingly. For example, Ethnologue's method of calculation consists in comparing a standardized set of wordlists and counting those forms that show similarity in both form and meaning. Using such a method, English was evaluated to have a lexical similarity of 60% with German and 27% with French.
However, this does not mean, that you can simply talk, read or understand German just by speaking English and hoping a non-English speaking German will understand you or vice versa. While nowadays, German has a lot of English words (especially of technical background) incorporated in its language, e.g. computer, monitor, keyboard, ... there are other words that are related but maybe not at first sight, e.g. house / Haus.
As pointed out in the comments, this depends heavily on the chosen words on the list and may not be overall conclusive.
In the end I'd like to point out, as mentioned in the comments, that this page is not really of remarkable quality and contains at least one plain wrong statement:
[...] or that the first printed book was written in German?
The first printed book (by the Gutenberg press anyway) was a bible in Latin. The first ever printed book seems to be in Korean: Jikji
English and German are West Germanic Languages. To this group also belong Dutch, Scots, Frisian and Low German. This means, they all have a common ancestor. This is simplified, since the ancestor was more or less a wide spread continuum of Germanic dialects. But fact is, that all West Germanic Languages developed big parts of their modern vocabulary form the same 1500 years old vocabulary.
But another fact is, that all of those languages had 15 centuries to develop apart from each other. And all of them imported words from other languages (like French or Latin).
Even more important: Their grammar did develop different.
So, it is no big surprise to find that sister-languages like English and German have a big amount of words that derive from the same old stem.
Examples are the words for close relatives:
- father - Vater
- mother - Mutter
- brother - Bruder
- sister - Schwester
- son - Sohn
- daughter - Tochter
- uncle - Onkel
- niece - Nichte
- nephew - Neffe
Or words for things that was know for long times:
- water - Wasser
- earth - Erde
- sun - Sonne
- moon - Mond
- rain - Regen
- snow - Schnee
Or parts of the body:
- arm - Arm
- hand - Hand
- fist - Faust
- foot - Fuß
- knee - Knie
- shoulder - Schulter
- hip - Hüfte
- arse - Arsch
- lung - Lunge
- heart - Herz
- nose - Nase
- ear - Ohr
- hair - Haar
But as you can read from all the given examples: Most of the words are not equal. They are just similar. So it very strongly depends on the definition whether you count them as same or as different.
So, a number like 60% easily can be changed into 10% or 40% just by changing the definition of what you consider to be equal.
Everybody will agree that pairs like bitter - bitter, hammer - Hammer, arm - Arm etc. are equal. But what about Austria - Österreich? Those words sound different, they even don't have much letters in common, but still both of them are derived from the same root Ostarricchi ("eastern realm") (the French name Autriche is somehow between Austria and Österreich). Are you willing to count them as equal? If not: Where to draw the border?